The healthy baby's blood points to the mothers
Three viruses show up in the sick babies and two in the healthy one; House realizes mothers' antibodies decide who survives.

Every House moment featuring Gregory House, in story order. Played by Hugh Laurie.
360 moments · 8h 56m · by Favseen
Moments 61–90 of 360
Three viruses show up in the sick babies and two in the healthy one; House realizes mothers' antibodies decide who survives.
Foreman is thrown when House asks about someone's well-being, and the two circle each other over why he wants to know.
Jill is thrilled by the news about her husband and wants House for her prenatal care. He has his own idea of the perfect gift.
House reads Cameron's awkwardness around dying patients and presses on who she lost, until she calls him what he is.
House won't drop the search for the virus carrier; later he refuses to leave a room by claiming a delivery for a patient due in five months.
Two weeks behind on charts and eager to clock out at noon, House stalls with poetry and juvenile tricks before being sent to a waiting patient.
Sister Augustine's red hands look holy to her companion; House traces them to a fresh batch of donated pots and hands out free antihistamines.
A nun explains God's will with a broken leg; moments later Sister Augustine can't breathe, House injects epinephrine and her heart stops.
Cuddy says the standard dose can't stop a heart and threatens to report him; House insists he gave the right dose and gets 24 hours to prove it.
The team settles on Churg-Strauss vasculitis, a gift of Christmas candy canes gets mocked, and House shuts down any suggestion he made a mistake.
A patient whose store job is on the line gets the most unusual prescription of his life, plus a promise that it will make him look cooler.
Accused again of the wrong dose, House counts down to a sarcastic 'admission', then pivots to mixed connective tissue disease and a hyperbaric chamber.
Cuddy warns that oxygen therapy can do harm; House mocks the oath's fine print and dares her to stop him.
An infirmarian warns House that Augustine is a hypochondriac; he catches her sinning on cue while she reads him right back.
With Augustine's oxygen falling after the chamber, Cuddy rejects every explanation House offers and removes him from his own patient.
Found poking through the epinephrine drawer, House argues lung cancer patients die of blame, then concedes he needs every clinic record checked.
Pumping Chase for what he knows about nuns, House offers his theory that good boys are trained by fear to obey their fathers.
At the monastery House catches the nuns in a shared lie, cites a tattoo he saw during CPR, and learns of Augustine's years on the streets.
As Augustine declines, House arrives with the monastery's herbal tea and shows how it plus a normal epinephrine dose stopped her heart.
House accuses Augustine of running away again and attacks belief itself; she answers with her own story and turns his anger at God against him.
House looks inside the patient for the allergen; the scan reveals a decades-old copper device, which explains everything from the cookware onward.
Sweating it out together, Wilson won't let House claim victory, they dance around Christmas plans, and a nun's farewell catches them off guard.
As an ER doctor blames Luke's mother's clot on vodka, House chimes in from the waiting chairs with mock praise for a doctor who never assumes.
The team mocks his interest in a schizophrenic's leg clot; House answers with ancient cures and a roll call of brilliant madmen.
House dispatches Luke on a very specific lunch order and sits with Lucy, while the team wonders why he is drawn to patients like her.
House turns his bedside chat into a lab order, Cameron meets a prickly Luke, and she quietly wishes House a happy birthday he never announced.
A mother wants House to scare her daughter off sugar before a party; he skewers her instead and prescribes a proper cake.
House mocks Foreman's claim that the drug was just a restraint, listing side effects that could wreck the diagnosis, then praises the fast lab work.
Vitamin K deficiency, an antibiotic interaction or alcohol: House pits his team's ideas against each other and sends them to find out.
Told the diet caused it, Luke insists he should have handled it; he gets brisk reassurance and admits he misses his mother bossing him around.